Tip o’The Day: Threadlocker & AntiSeize

Many automobiles can go 100,000 miles or so without ever suffering from a screw or bolt coming loose. Yet just about every motorcycle owner has, at one time or another, suffered the frustration of having a part rattling and buzzing (or even falling off) because of a loose fastener.

The motorcycle environment is pretty tough on fasteners. Bike tend to vibrate more than cars, most fasteners are  exposed to the elements, and generally speaking bike fasteners are smaller diameter than their automotive equivalents. Because the fasteners are on display – manufacturers are loath to put lockwashers under the heads. Plus, motorcycle owners are more likely to do some home wrenchin’ themselves – which adds a whole other dimension to the problem.

To save yourself the indignity, and expense, of having parts come loose on your bike, no motorcycle owner should be without a tube of threadlocker in their toolbox.

Chemical threadlocking agents are special because they cure in the absence of air (anaerobically) which allows them to be used in threaded fasteners. There are actually several companies that make threadlocker, Loctite being one brand, but also Permatex. These different companies put their products in different colored bottles, so check carefully when chosing them.

For most motorcycle applications you will want a Medium Strength threadlocker – Loctite 242 “Blue”, or similar. There are high-strength compounds, Loctite 271 “Red” – but these are meant for fasteners that rarely require removal, and usually require heating with a torch before removal. To apply threadlocker, simply place a few drops on the threaded part of the screw and insert it. Theoretically blind holes should have threadlocker applied to both surfaces for best adhesion. Properly prepared fasteners will generally resist unintended loosening, and require a firm “snap” with the appropriate tool to loosen.

Some fasteners and shafts on the motorcycle require different treatment – specifically an anti-seize compound. As the name implies, anti-seize prevents such fasteners and shafts from seizing in place. Typically anti-seize will be used on suspension bolts, and should always be liberally applied to axles. There are high-temperature anti-seize compounds, and these may be used on the junction between exhaust bodies and header pipes.